"Many different studies show 300, 400, 500 percent increases in reports of bed bugs or reports of bed bug infestations," said Dr. Jerome Goddard, an entomologist with Mississippi State University.

The bed bug resurgence is due to international travel, immigration and changes in pest control practices, Goddard said. Since bed bugs can spread easily by hitching a ride on luggage, any venue can be infested.

"It has nothing to do with how clean you are. Some of the cases I've investigated, they've been five-star hotels," Goddard said.

Bed bug bites often cause an itchy rash or red bumps, but it's unclear how dangerous human reactions to bed bug bites are. Few people with bed bug bites come to clinics to be studied.

"Some scientific papers say that bed bugs transmit human diseases; some say they don't," Goddard said. "Some people say you're supposed to throw out the mattresses when there's an infestation of bed bugs; some say you don't."

Goddard analyzed research from more than 50 investigations of bed bugs and published his results in the Journal of the American Medical Association.

"The research findings show (that) there is little evidence for human disease transmission by bed bugs," he said.